#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <cstring>
#include <string>

#define ID_GENERATE 100

#define WINDOW_X 350
#define WINDOW_Y 270

LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);

bool DrawSometing(HDC hdc, int lines, int x = WINDOW_X, int y = WINDOW_Y){
    int a, b;
    for(int i = lines; i > 0; i--){
            srand(clock());
            a = rand()%x+1;
            b = rand()%y+1;
            LineTo(hdc, a, b);
            Sleep(1);
    }
    
    return true;
}
char szClassName[ ] = "WindowsApp";

HWND g_hGenerate;
HWND hText;
HWND hwnda;
HDC hdc;

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
    HWND hwnd;             
    
    MSG messages;         
    WNDCLASSEX wincl;       

    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      
    wincl.style = CS_DBLCLKS;              
    wincl.cbSize = sizeof (WNDCLASSEX);

    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 
    wincl.cbClsExtra = 0;                     
    wincl.cbWndExtra = 0;                     
    
    wincl.hbrBackground = NULL; // (HBRUSH) COLOR_BACKGROUND
    
    if (!RegisterClassEx (&wincl))
        return 0;

    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "Windows App",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           WINDOW_X,                 /* The programs width */
           WINDOW_Y,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );
           
     g_hGenerate = CreateWindowEx( 0, "BUTTON", "Kliknij mnie", WS_CHILD | WS_VISIBLE, 5, 190, 150, 30, hwnd, (HMENU)ID_GENERATE, hThisInstance, NULL);
     hText = CreateWindowEx( WS_EX_CLIENTEDGE, "EDIT", NULL, WS_CHILD | WS_VISIBLE | WS_BORDER, 160, 190, 150, 20,
hwnd, NULL, hThisInstance, NULL );
    ShowWindow (hwnd, nFunsterStil);
    
    hdc = GetDC(hwnd);
    while (GetMessage (&messages, NULL, 0, 0))
    {
        TranslateMessage(&messages);
        DispatchMessage(&messages);
        
        
    }
    return messages.wParam;
}


LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_COMMAND:
             switch(wParam){
                            case ID_GENERATE:
                                 
                                 DWORD lngth = GetWindowTextLength(hText);
                                 LPSTR Bufor = (LPSTR)GlobalAlloc(GPTR, lngth+1);
                                 DrawSometing(hdc, GetWindowText(hText, Bufor, lngth+1));
                                 GlobalFree(Bufor);
                                 break;
                            
                            
                            }
             break;
        case WM_DESTROY:
            PostQuitMessage (0);     
            break;
        default:                      
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}

